METHODS OF PURIFYING EFFLUENTS FROM THE MANUFACTURE AND BLEACHING OF WOOD PULP

摘要

Procedure for the purification of the effluents of the manufacture and bleaching of chemical and semi-chemical paper pulps, by means of aluminum sulfate, characterized in that a part of the non-biodegradable materials, present in the waters to be treated, precipitates in a first stage by the addition of excess aluminum sulfate, the solution obtained then being subjected, after separation of the precipitates formed, in a second stage, to flocculation due to the excess of aluminum sulfate remaining in solution, with pH adjustment to value, or to a very close value, of 5.4, separating the precipitates and flocculates formed during the two stages of the process and treated in order to allow the recovery of the aluminum sulfate. (Machine-translation by Google Translate, not legally binding)